Type selection mechanism



J. E. HICKERSON TYPE SELECTION MECHANISM Sept. 22, 1959 2 Sheets-Sheet 1 Filed Dec. 51, 1957 FIG.2

INVENTOR.

JOHN E. HICKERSON 4, KM

FIG. 3

ATTORNEY United States Patent 6 i TYPE SELECTION MECHANISM John E. Hickerson, Lexington, Ky., assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Application December 31, 1957, Serial No. 706,461

Claims. (Cl. 101--93) This invention relates to a printing device and more specifically to a print element selection mechanism utilizing a print element carrier which is positioned with respect to a print position by foreshortening a control cable.

In this general type of device, various characters mounted on the print element carrier are selected by foreshortening the various wire increments. In this type of device one problem is encountered in as much as, for a large increment of movement of the print element carrier, the acceleration of that carrier is great as compared with the acceleration when a smaller increment of movement is effected.

Accordingly, a primary object of this invention is to provide a print element selection mechanism wherein the acceleration of the print element carrier is uniform for all increments of selection movement.

A further object of this invention is to provide a selection mechanism utilizing an inclined ramp, the incline of which is varied according to the magnitude of the increment of movement required to select a desired character.

Another object of this invention is to provide a selection mechanism utilizing an inclined ramp, the incline of which is varied according to the magnitude of the increment of movement required to select a desired character and is controlled by selectively sett-able stop pins.

A further object of this device is to provide a type selection device wherein a next character may be selected before the operating parts return to their normal positions.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Figure 1 is a partial elevation showing a segment of the device.

Figure 2 is a perspective view showing a key operable for actuating binary coded contacts as well as a universal bail and associated contacts.

Figure 3 is a perspective view showing a pin selection Referring to Figure 1, a type wheel or type element.

carrier is rotatably mounted on a base plate 12. An inclined ramp element 14 is pivotally mounted on the base plate 12 about an axis 16. The element 14 is of inverted U shaped cross-section partly broken away in Figure l, and is biased in a clockwise direction by a spring 18 fixed at its other end to a pin 20 carried by the base plate 12. The element 14 is normally biased against a stop pin 22 mounted on the base plate.

The base plate contains eleven holes 24 arranged in an arc. The lowest hole 24 contains a fixed pin 26 whereas the remaining ten holes are adapted to receive movable stop pins 28 shown in Figures 3 and 4. The stop pins 28 are interposable into the path of the nose 30 of an eleice ment 32 pivoted by a pin 34 onthe element. 14 and biased in a clockwise direction about the pin 34 by a spring 36 attached at the other end to a finger 38 on the element 14. The spring 36 biases the element 32 against a stop pin 40 also carried by the element 14. t

A print hammer 42 is pivotally mounted on the plate 12 at a point 44 and is biased in a counterclockwise direction by a spring 46 connected to a pin 47 mounted in. the base plate. The hammer 42 is biased against a stop pin 48 carried by the base plate. A cam 50 is mounted on a shaft 51 adjacent the hammer 42, and a lobe 52.0n the cam 50 is adapted to actuate the hammer 42, each time the cam is rotated, to press a ribbon 54 and a record sheet (not shown) against a type element 56 positioned adjacent the hammer.

An arm 58 is pivotally and slidably mounted in a slot 60 formed in a member 62 fixed to the base plate 12. The arm 58 pivotally mounts a pulley 64. A wire or cable 66 is fixed to the plate 12 at a point 68 and is threaded over the pulley 64 and a pulley 70 also rotatably mounted on the base plate, around a pulley 72 on the' print element carrier 10, to a spring 74 fixed to the plate.

12 by apin 76. p

A wheel 78 is pivotally joined to the opposite end of the arm 58 and also to an arm 80, the axis of the wheel 78 being normally coaxially with the axis 16. The arm 80 is normally biased to the right by a spring 82 fixed to the plate 12 by a pin 84. The opposite end of the arm 80 is pivotally joined at a point 85 to an arm 86 which is pivotally fixed at a point 88 to the base plate. Intermediate the points 85 and 88, the arm 86 rotatably mounts a cam'follower 90. The cam follower 90 follows a cam 92 pivotally mounted on the base plate 12 by a shaft 94. When the shaft 94 and the cam 92 fixed there to are rotated, the cam follower 90 and the member 86 are driven to the left to the dotted outline positions in Figure 1. In'the dotted outline positions the same reference numbers are used with a suffix a. The driven member 86 through the arm 80 draws the roller 78 and arm 58 to the left to their dotted positions. The downward component of force of the spring 82 causes the element 14 to pivot in a counterclockwise direction about its axis 16 until the nose 30 of the element 32 encounters one of the pins 28 or, in the event that a pin 28 is not actuated, the fixedpin 26. If the element 14 is stopped by the pin 26 (as shown at 14a in Figure 1), the roller 78, rolling along the upper surface of the element 14, effects no upward movement of the pulley 64 and consequently no rotation of the print element 10. In this event a blank position normally adjacent the print ham mer remains adjacent thereto and a character is not printed. However, if a pin 28 is interposed in the path of the element 32, the pulley 64 will be elevated an in crement proportional to the distance from the normal position of the element 32 to interposed pin 28 and will effectively foreshorten the cable 66 thereby rotating the print element carrier 10 and positioning a digit type ele ment corresponding to the interposed pin 28 opposite the print hammer 42. The cam 92' and the cant 50 are actuated in a manner described hereinafter.

Referring to Figure 2, a key 96 having a stem 98 is shown. This key has the dual purpose of actuating a universal bail 100 pivotally mounted on pins 102 and carrying one contact of a pair of contacts 104. Theother contact of the pair is mounted adjacent the bail and is adapted to be closed when the'key 96 is depressed thereby pivoting the bail 100 aboutthe pins 102. The key stem 98 also carries a finger 106 adapted to operate one or more pairs of contacts 108.

In Figure 4,- ten digit keys, designated 96-1 dan e 96-0, are schematically shown along with. the contacts operated by each key. With reference to Figure 4 it will be noted that the contacts 108 are binary coded in the well known 1, 2, 4, 8 code as indicated at the right end of Figure 4. It will be noted that one side of each of the contacts 108 is connected to a plus potential terminal 110. The opposite side or the "1 contacts are common connected to a solenoid 112-1; the opposite side of the 2 contacts are common connected to a solenoid 112 -2; the opposite side of the "4 contacts are common connected to a solenoid 112-4; and the opposite side of the 8 contacts are common connected to a solenoid 112-8.

The solenoids 112-1 through 112-8 are connected to respective slidable code bars 114-1 114-2, 114-4, 114-8'. These code bars 114-1 through 114-8 contain coded notches of two types, the first type designated 116-a are normally out of alignment with ten pin actuating bars 118-1 through 118-0. The other type of coded slot is designated as 116-b and is normally in alignment with the ten actuating bars 118. .Code bar chart- X- code notch 116a Blank=code notch 11Gb Referring to Figure 3, the code bars 114-1 through 114-8 are shown with five of the pin actuator bars 118 and five of the pins 28 described hereinbefore't A cam 120, pinned to a. rotatable shaft 122, is positioned adjacent the pin actuator bars 118 and is common to all ten of the bars 118. The pin actuator bars 118 are biased in a clockwise direction about their pivot points 124 by springs 126 and are normally restrained against the spring 126 by the high lobe of the cam 120. In Figure 3 the cam has rotated sufiiciently to release the bars 118 and bar 118-1 is. shown as actuated. When the code bars 114-1 through 114-8 are actuated in various combinations according to the key 96 which is operated, and, when the cam 120 is rotated to release the restraining action on the actuator bars 118, the springs 126 tend to pivot all bars 118 in a clockwise direction; however, only those bars 118 in which all the notches 116a correspond ing thereto are shifted to non-interposed positions with respect thereto may be pivoted to actuate a corresponding pin 28 against the biasing action of its spring 128. Upon completion of one rotation of the cam 120, the cam restores any actuated bars 118 to their normal positions, thus permitting the springs 128 to restore any actuated pins 28. The code bars 114 are returned to their normal positions by springs 130 when the solenoids 112 are deenergized.

As illustrated in Figure 4, the bail 100 is actuated by any key 96 which is depressed and the contacts 104 when closed complete a circuit from the plus terminal 110, in parallel through three clutch magnets 132,- 134 and' 136, to ground at 137.

The drive means for this device is represented by the shafts 51, 94 and 122. This drive means may be any conventional motor which, through appropriate gearing, can drive the shafts 51, 94 and 122 at desired speeds. However, these shafts are not driven directly but are connected with the motor through one revolution electromagnetic clutches 132,- 134 and 136.- The clutch 132 connects the shaft 94 for rotation to position the print element carrier 10; the clutch 134 connects the shaft 51 for operation of the print hammer; and the clutch 136 connects the shaft 122' for operation of the earn 120.

This type of drive and one revolution clutch is well known and further illustration is not deemed necessary.

In operation, depression of a key first closes the corresponding contacts 108 to actuate corresponding solenoids 112 thereby positioning the corresponding code bars 114. Simultaneously, the clutch 136 is energized to rotate the cam 120 to release the pin actuator bars 118, the code bars 114 and the actuator bars 118 cooperating to set a particular pin 28 After the pin 28 is set, the clutch 132 is energized to rotate the cam 92 and drive the elements 86, 8G, 78 and 58 to the left. As described hereinbefore, through the spring 82, the arm and the roller 78, the inclined element 14 is rotated until the nose 30 engages the set pin 28. The pulley 64 is elevated in accordance with the pin 28 which is set and,- thro'ug'gh the cable 66, rotates the element 10 to position a corresponding character adjacent the print hammer 42.

The timing relation of the solenoids may be controlled by having the contacts 108 closed before the contacts 104. The timing of the clutches 132,134 and 136 may be effected by selecting clutches with different pick up times whereby they pick up in the desired sequence. The timing also could be effected by having contacts operated by one clutch complete the circuit to the next clutch; however this requires a more complex circuit and is a conventional way of controlling timing.

As described hereinbefore, the element 32 is pivotally mounted and is biased by the spring 36. The purpose of this construction is to permit selection of a following pin 28 prior to the element 14 being restored to its normal position. Assuming the dotted outline position in Figure 1, in which the print hammer strikes a blank space on the element 10, it will be desirable, in the interest of speed, to select the pin 28 corresponding to the next character before the element 14 is restored. If this selection is made prior to restoring the element 14, the element 32 during its return movement will strike the newly set pin. The element 32 is then pivoted counterclockwise about the in 34 and passes by the pin 28. The element 14 may be immediately actuated again to come to rest against the newly set pin for selection of the desired character.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilledin' the art without departing from the spirit of the invention. It is the intention therefore, to be limited only as indicated by the following claims.

What is claimed is:

, l. A print element selection device comprising, in com- !bination, a character bearing element movable relative to a print position for aligning said characters individually with said print position, a print hammer'adjacent said print position, means operable for actuating said print hammer, a pivotally mounted inclined plane, means biasing said plane in one direction about said pivot, a plurality of pins selectively interposaible for limiting the extent of movement of said plane in an opposite direction, a corresponding plurality of pin actuators biased in a direction to interpose corresponding pins and normally held in an inoperative position, a cam operable to first release said pin actuators and then to restore said pin actuators to said inoperative position, a plurality of code bars containing coded notches and selectively operable to align said coded notches to permit operation of said pin actuators, a follower element operable for following said inclined plane and for pivoting said plane against said interposed pin, means for operating said follower, means operable by said follower for moving said character bearing element an amount inversely proportional to the displacement of said plane as determined by the actuated one of said interposable pins.

2. A print element selection device comprising, in combination, a character bearing element movable relative to a print position for aligning said characters individually with said print position, a print hammer adjacent said print position, means operable for actuating said print hammer, a pivotally mounted inclined plane, means biasing said plane in one direction about said pivot, a plurality of pins selectively interposable for limiting the extent of movement of said plane in an opposite direction, a corresponding plurality of pin actuators biased in a direction to interpose corresponding pins and normally held in an inoperative position, a cam operable to first release said pin actuators and then to restore said pin actuators to said inoperative position, a plurality of code bars containing coded notches and selectively operable to align said coded notches to permit operation of said pin actuators, a cable operatively engaging said character bearing element, an eccentric cam operable for operating said plane follower, a pulley movable with said plane follower and operating through said cable for moving said character bearing element an amount inversely proportional to the movement of said plane as determined by the actuated one of said pins.

3. A printing mechanism comprising, in combination, a character bearing element movable relative to a print position for aligning its characters individually therewith, means for eifecting a printing by any one of said characters when moved to said print position, means for moving said element to present said characters selectively to said print position, said moving means comprising a plane member free at one end and pivotally supported at its other end, means yieldingly urging said plane member to an inclined position, means selectively positionable for limiting the angular movement of said plane member from its inclined position, an elongated member having one end normally in operative engagement with said plane member at its pivoted end, means slidably supporting the opposite end of said elongated member for movement in a plane substantially normal to said plane member adjacent its free end, means connecting said elongated member to said character bearing element for moving the latter in response to movement of said elongated member on said supporting means, and means for moving said one end of said elongated member over said plane member to eifect an angular movement of the latter against said limiting means and a sliding movement of said elongated member a distance inversely proportional to the angular movement of said plane member.

4. The mechanism of claim 3 in which said means connecting said elongated member to said character bearing element comprises a flexible element engaging pulleys supported by said elongated member and said character hearing element respectively.

5. The mechanism of claim 3 in which said limiting means comprises pins selectively movable through open ings in the path of angular movement by the free end of said plane member, and an element carried by the free end of said plane member and engageable with one of said pins for interrupting angular movement in one direction, said element being deflectable on engagement with a pin when moved in the opposite direction to permit free movement of said plane member.

References Cited in the file of this patent UNITED STATES PATENTS 444,750 Green Jan. 13, 1891 638,092 Carmona Nov. 28, 1899 723,567 White Mar. 24, 1903 2,661,683 Beattie Dec. 8, 1953 2,746,384 Bradley et a1. May 22, 1956 

